The Detroit Lions have released veteran defensive end Kyle Vanden Bosch.

Detroit Lions head coach Jim Schwartz was waiting on Vanden Bosch’s doorstep the minute free agency opened in 2010.

The Lions needed an upgrade both on the field and in the locker room, and Schwartz convinced Vanden Bosch to sign a four-year, $26 million deal to help Detroit’s rebuilding process.

The Vanden Bosch signing immediately paid dividends on the practice field, on game day and in the locker room, which the Lions sorely needed at the time, just two year’s removed from 0-16.

Vanden Bosch was one of the key acquisitions that helped put the Lions back on the map.

But now entering the final year of that deal, Vanden Bosch, 34, has seen his production decline and his salary cap figure increase, which led to Tuesday’s decision to release the 12-year veteran.

Vanden Bosch had 3.5 sacks last season – his lowest total since 2009 – and his salary cap number for 2013 was scheduled to be over $10 million. He was also set to make a $2 million roster bonus.

The Lions saved $5 million towards the 2013 salary cap by releasing him.

Vanden Bosch has been nothing but a consummate professional since joining the Lions, taking some of the younger defensive ends under his wing.

Cliff Avril has credited Vanden Bosch a number of times over the last couple years for helping him become the player he is now, which is one of the top free agents pass rushers on the market this offseason.

"I would dedicate the majority of my success and how I’ve turned my career around to him," Avril said after the season. "I have so much respect for him and how he approaches the game. He’s basically taught me how to become a pro."

The Lions entered the week approximately $3 million over the projected $121 million salary cap. Vanden Bosch’s release is a reality of life in the NFL under the salary-cap rules.